Of course you can also add a single chain, or thick steel cable, anchored to an eye-bolt screwed into a garage structural part, or into an anchor in the floor. Not totally unbreakable, but will take a few minutes to break. Threaded through the frame opening of all the bikes. Breaking or cutting that will take at least a minute, and if the alarm system is at least 120 Decibels it will provoke a panic among the bad actors. Flashing strobes also make it harder for them to focus. AND if the alarm triggers before the door is opened very wide they might not even get inside. And the good ting about such an arrangement is that if it is triggered accidentally no injuries result. An actual farm livestock fence charger hooked to the cain restarining the bikes could seroiusly slow the bad actors a bit more. Painful but not lethal.

Like the idea of the farm fence ,,
but in case others look, certainly in the UK,
doing so is looked on badly by the police, and you will be arrested as "unreasonable force" esspecialy if youhave not put big light signs every where !

Ask me how I know

 

It does not appear that the TS is in the UK. And it is certainly possible to have a fence charger easily removable. And it is also possible to have a poorly-wired alarm lighting system accidentally connecting the hot side of the line to that security cable run through the bikes. Short circuits due to wiring incompetence would be OK, here in the USA juries seem to always excuse incompetence .

But really, just making a whole lot of noise with bright lights should tend to make most ba actors run.

 

It does not appear that the TS is in the UK.

Southern Arizona according to the TS in post #12.

 

It does not appear that the TS is in the UK. And it is certainly possible to have a fence charger easily removable. And it is also possible to have a poorly-wired alarm lighting system accidentally connecting the hot side of the line to that security cable run through the bikes. Short circuits due to wiring incompetence would be OK, here in the USA juries seem to always excuse incompetence .

But really, just making a whole lot of noise with bright lights should tend to make most ba actors run.

In UK,
if you had wiring that accidently made something live,
and it caused harm to some one,
As its "outside" you would be asked by authorities for certificate of completion for the work by the competent engineer who installed it
if you did wiring yourself, and it was found not to be "to code" you are liable,

Heads they win, tails you loose,

 

In UK,
if you had wiring that accidently made something live,
and it caused harm to some one,
As its "outside" you would be asked by authorities for certificate of completion for the work by the competent engineer who installed it
if you did wiring yourself, and it was found not to be "to code" you are liable,

Heads they win, tails you loose,

The whole thing is INSIDE A LOCKED GARAGE! Thus breaking and entering have already been committed prior to anyone touching the bikes. WE are not discussing bicycles parked out on the front lawn here.
This is inside of a locked garage.
AND, if one injures an invader it is ALWAYS prudent to remove any weaponry PRIOR to notifying any authorities.

 

Mr. Policeman, I do not know how the intruder got beheaded.

 

Mr. Policeman, I do not know how the intruder got beheaded.

But it seems that I yelled and the guy turned and tripped over the weeding knife somehow.

 

if you had wiring that accidently made something live,
and it caused harm to some one,

so just need to be done intentionally and on purpose, rather than accidentally

 

Mr. Policeman, I do not know how the intruder got beheaded.

place camera and keep the footage of the incident (sans prudent removal of the weaponry)

 

If the garage has an air compressor with a big air tank then it is also possible to use a solenoid air valve to sound a very loud air horn, or an even louder air powered whistle. You can make a painfully loud noise with 120PSI and a ten gallon air tank, easily 120 decibels, or even louder. Certainly far above the threshold of pain. How about 3 KHZ and 135 Db?? And a second whistle at perhaps 4500Hz. Use 3/4 inch pipe and make the whistle with half inch tube. Easy to do, and it can wake every dog for many miles around. With an adequate reflector, like from a discarded satellite dish you can gain another 6dB.
WE are talking several acoustic HORSEPOWER here! Way beyond ear-bleeding loud. All inside a closed garage. Hope it doesn't peel the paint off of the bikes. THAT will chase away the bad guys.

 

If the garage has an air compressor with a big air tank then it is also possible to use a solenoid air valve to sound a very loud air horn, or an even louder air powered whistle. You can make a painfully loud noise with 120PSI and a ten gallon air tank, easily 120 decibels, or even louder. Certainly far above the threshold of pain. How about 3 KHZ and 135 Db?? And a second whistle at perhaps 4500Hz. Use 3/4 inch pipe and make the whistle with half inch tube. Easy to do, and it can wake every dog for many miles around. With an adequate reflector, like from a discarded satellite dish you can gain another 6dB.
WE are talking several acoustic HORSEPOWER here! Way beyond ear-bleeding loud. All inside a closed garage. Hope it doesn't peel the paint off of the bikes. THAT will chase away the bad guys.

And I just can't wait for a false alarm to be triggered. Never mind protecting property - the neighbors may be out for blood. Especially with numerous false alarms.

 

never say never, BBQ and some beer can go long way

 

And I just can't wait for a false alarm to be triggered. Never mind protecting property - the neighbors may be out for blood. Especially with numerous false alarms.

Using a mechanical trip

 

Using a mechanical trip

True. But I worked with a handicapped kid who had a van with an automatic tailgate that could be lowered by the press of a switch. Living in the snow belt, salt worked its way into the switch, and while up on the highway the doors opened and the gate started to come down while he was driving. He was able to get pulled over just as the gate hit the ground. Even mechanical switches can fail in one fashion or another. Perhaps to reduce the chance of a switch failure, dual switches wired in series can suffice adequately. And in the event of an unlikely false alarm, a main shut-off switch should be incorporated somewhere in circuit.

Have you ever worked on a major piece of power equipment - the sort that could rip a mans arm off or crush a hand? Simply depending on the ON/OFF switch to protect the maintenance worker is something that I wouldn't want to do. Either a breaker with a LOCK-OUT/TAG-OUT device to prevent accidental triggering is industry standard. And in many cases I've seen incorporate a plastic box that you put the plug inside and lock it closed so that nobody else thinks "oh, I bet this is supposed to be plugged in." OK, I'm over-thinking this. My comment about false alarms was intended somewhat to be light hearted. Still, it shouldn't be overlooked.

 

I always wanted to make an alarm system with - instead of an alarm - a recording of a woman screaming bloody murder. I'm sure that'd make the would be thieves swallow their back teeth when the sound of a woman screaming bloody murder (from an old movie). Definitely more fun than practical but I don't think they would stick around to find out.

No, I'm not asking how to build such a device, just making a comment about alarms that scare thieves. You could just as easily use the sound of vicious barking dogs. But an alarm and strobe light will be more than sufficient.

I have plans to build an alarm that sounds like a "electrical gun charging up" or robot getting into position, popular in the movies where the main character then has enough time to dive out of the way before the weapon fires.

@TS, an Arduino or Pi could be used to provide data when potential culprits are even in the area lurking around, how often they come and go etc. A long term goal of mine is to have a raspberry pi protecting every area of my home with cameras recording upon detection and email alerts.

 

I always wanted to make an alarm system with - instead of an alarm - a recording of a woman screaming bloody murder. I'm sure that'd make the would be thieves swallow their back teeth when the sound of a woman screaming bloody murder (from an old movie).

You know the Aztec actually used a curious "whistle" that could do just that. Hook a few of those suckers up to some kind of air pump system and the result I am sure would be rather impressive!

 

I once for into trouble for having 20 of these in my uncles shop hooked into the alarm .
https://www.tlc-direct.co.uk/Produc...bhpvHWXXd3tTqwD1EM4T-ettMYJS--QIaAr6qEALw_wcB
He'd been burgled twice , these and strobe lights , and CCTV the Burglers were caught , but
Police arrested me after burglers said they now had tinitus
I ended up with caution on police record ,
But uncles shop was never burgled again ...
I'm not police , it's just a heads up

 

True. But I worked with a handicapped kid who had a van with an automatic tailgate that could be lowered by the press of a switch. Living in the snow belt, salt worked its way into the switch, and while up on the highway the doors opened and the gate started to come down while he was driving. He was able to get pulled over just as the gate hit the ground. Even mechanical switches can fail in one fashion or another. Perhaps to reduce the chance of a switch failure, dual switches wired in series can suffice adequately. And in the event of an unlikely false alarm, a main shut-off switch should be incorporated somewhere in circuit.

Have you ever worked on a major piece of power equipment - the sort that could rip a mans arm off or crush a hand? Simply depending on the ON/OFF switch to protect the maintenance worker is something that I wouldn't want to do. Either a breaker with a LOCK-OUT/TAG-OUT device to prevent accidental triggering is industry standard. And in many cases I've seen incorporate a plastic box that you put the plug inside and lock it closed so that nobody else thinks "oh, I bet this is supposed to be plugged in." OK, I'm over-thinking this. My comment about false alarms was intended somewhat to be light hearted. Still, it shouldn't be overlooked.

I have worked on the controls for all sorts of big machines, from production line engine engine dyno's to automatic transmission testers, and a lot of others. All sorts of high force motion involved. They could easily mash a person. Also showed folks how to use a lathe to recover welded fittings. So I am well aware of both the hazards and the ways to reduce them. For machines, the first line, during use, is the latching "E-STOP" button, set to unlatch the power for all motion actions. This button is a maintained position device, meaning that to restart the button must be manually pulled back out to allow the contacts to close. In addition, that portion requires a second button, (START) to be operated to energize the motion system power. Every element in the controls is designed for life-critical reliability, and the design is such that at least three elements would need to fail to cause an unsafe malfunction, while if a single element failed the system can not start.
In addition to that, all of the systems include a lockable main power disconnect switch to remove all power to every system.
All of this is the basic safety arrangement, but also a whole lot of machine specific effort is included.

SO, YES, I am quite aware and well practiced in making things safe. Big ones and small ones a well.

In reference to the handicapped person's automated powered tailgate, I point out that those types of installations are often done with no consideration beyond following some mandatory rules that were created by those seeking to avoid legal liability, and lacking actual understanding. And almost always, the system parts are elected for minimum cost, not long life. AND, actual roadway salt spray is far more brutal than the military salt-spray test.

 

I once for into trouble for having 20 of these in my uncles shop hooked into the alarm .

Or you could spill HOT coffee on your lap and sue the place you purchased it from. Sadly, a case of the victim becoming the victor. You can CATCH them but you have to catch them "Nicely". That's why I won't own a vicious dog.

 

In reference to the handicapped person's automated powered tailgate, I point out that those types of installations are often done with no consideration beyond following some mandatory rules that were created by those seeking to avoid legal liability, and lacking actual understanding. And almost always, the system parts are elected for minimum cost, not long life. AND, actual roadway salt spray is far more brutal than the military salt-spray test.

I unplug power equipment before changing bits and blades. Do you?